A spherical drop of water has radius 1 mm if surface tension of water is 70 × 10-3 Nm-1, difference of pressure between inside and outside of the spherical drop is

1) 35 Nm -2

2) 70 Nm -2

3) 140 Nm -2

4) zero  

A spherical drop of water carrying a charge of 30 pC has a potential of 430 V at its surface (with V = 0 at infinity). (a) What is the radius of the drop? (b) If two such drops of the same charge and radius combine to form a single spherical drop, what is the potential at the surface of the new drop?

A spherical drop of water carrying a charge of 25 pC has apotential of 475 V at its surface (with V = 0 at infinity).
(a) What is the radius of the drop?

(b) If two such drops of the same charge and radius combine to forma single spherical drop, what is the potential at the surface ofthe new drop?

A spherical drop of water carrying a charge of 31 pC has apotential of 530 V at its surface (with V = 0 at infinity).
(a) What is the radius of the drop?
m

(b) If two such drops of the same charge and radius combine to forma single spherical drop, what is the potential at the surface ofthe new drop?
V